So-called brightness-increasing films improve the brightness of area luminescence equipment such as liquid display equipment. FIG. 1 shows one example of such an area luminescence equipment.
In the example shown in FIG. 1, light from a surface light source 91 is supplied to a lower diffusive plate 92 through an air layer 94-1, and light transmitted to the lower diffusive plate 92 is diffused/emitted and then supplied to an optical film 93 through an air layer 94-2. Light supplied to the optical film 93 penetrates the optical film 93 and transmitted light is directly supplied to an upper diffusive plate 96 through an air layer 94-3, diffused/emitted and then supplied to an illuminating body 97 (liquid crystal display panel) through an air layer 94-4. The phrase “through the air layer” means that adjacent parts (e.g., surface light source and lower diffusive plate, etc.) are not optically closely contacted.
When constructions such as shown by FIG. 1 include a large number of parts, manufacturing operations can become complicated. In the optical system composed of a combination of these parts, since the area of the optical surface increases (an interface between the surface of parts and an air layer), the optical loss by surface reflection on the optical surface increases and the light transmitting efficiency is lowered. Therefore, it can be difficult to improve the brightness of the area luminescence equipment.
The present invention provides an optical laminated body which can reduce the number of parts, and thereby simplify operation and production of the optical laminated body, and minimize the number of optical surfaces of the optical system, thereby preventing optical loss by interfacial reflection and enhancing the brightness of an area luminescence equipment. Lighting equipment and area luminescence equipment using such optical laminated bodies are also provided.